The present invention relates to pad printers. More particularly, the present invention relates to a digital cliché pad printing system and method.
Pad printing systems are used to apply high quality print, e.g. indicia. Pad printing systems use a deformable pad which receives ink, transferred as an image, from a cliché plate. The plate has an etching or engraving of the indicia formed therein. The image is transferred from the pad to the item onto which the indicia is applied.
These systems work well to produce high quality image transfer and for transferring images onto flat, as well as textured and non-planar surfaces. One drawback to the pad printing method is that cliché plates are expensive to fabricate, e.g., prepare, etch, and mount. As such, short run or single run printing is cost prohibitive using a pad printing method.
Digital systems (e.g., laser or ink jet printing) are often used for short run or single run printing due to the flexibility of these systems. These methods lend themselves well to short run and single run printing because printing commands such as image shapes are purely machine controlled. Accordingly, much lower costs are incurred in changing over the image to be printed or transferred.
It has been found that digital printing is however, limited in practical application to symmetrical shapes (e.g., spheres, cones, cylinders) or to flat or near-flat applications that allow the print head to remain within a narrow stand-off distance from the surface of the object (typically within a distance of about 0.5 to about 2.5 mm).
Other solutions to enable the flexibility of digital printing in a pad system include directly jetting ink onto the printing pads which is then transferred onto the object surface. It has however been found that inks that “jet” are not well suited for pad transfer, and often smudge or smear resulting in unacceptable image transfer.
Accordingly, there is a need for a digital cliché pad printing system and method. Desirably, such a system and method permit the use of a cliché in single run and short run printing applications. More desirably, such a system and method provide high quality image transfer without the costs associated with conventional cliché preparation.